The invention relates to an inserting means for tubular, fiberoptic instruments, especially colonoscopes, gastroscopes, and the like, comprising a grip part and a flexible insertion part adapted to be pushed into an object to be examined, especially the human colon and including, between an inner wall and an outer wall, at least one intermediate space which is sealed outwardly and into which a fluid can be introduced. The outer wall of the insertion part is formed by a flexible hose which, however, is not inflatable like a balloon by the fluid in the intermediate space. The inner wall of the insertion part likewise is formed by a hose, and The intermediate space contains support elements through which the inner wall and the outer wall are mutually supported when the pressure in the intermediate space fails to reach a predetermined value.
An inserting means of this kind is known from U.S. Pat. No. 4,815,450. There the intermediate space contains ball shaped support elements between the inner and outer walls of the insertion part which elements are freely disposed and therefore movable in the intermediate space. As a consequence, the support elements may become shifted in the intermediate space and consequently do not always reliably fulfill their task of stiffening the insertion part when there is a vacuum in the intermediate space. The user therefore cannot rely on the inserting means keeping a particular desired configuration during a particular manipulation of a colonoscope or the like.
As is known, for example, from U.S. Pat. No. 4,696,544, there are fields of application for tubular fiberoptic instruments outside of the medical field, too, such as for examining pipelines, vessels, and machine parts. The term "object to be examined" is to be understood accordingly in the context of the present invention.
For inserting colonoscopes, also inserting means are being used which have a one-piece slip tube which is of great flexural stiffness as compared to the corresponding colonoscope and permits only relatively minor elastic bending. The inner diameter of such a slip tube for a colonoscope having an outer diameter of 15 mm, for instance, is barely 16 mm so that the colonoscope can be pushed through easily any time. The outer diameter of the slip tube is 19 mm, for example. The insertion part is 40 cm long. The length of the associated colonoscope usually is between 130 and 180 cm. A distal end portion, approximately 10 cm long, of the colonoscope usually can be moved in four directions (up/down and left/right) by means of setting wheels supported at the proximal end.
The physician performing an examination or treatment pushes the colonoscope from the anus into the colon. The colonoscope must be advanced up to the cecum in order to permit full examination of the colon. In doing that, the direction of movement of the colonoscope can be determined by its movable distal end portion. However, at the bends of the colon, namely at the sigmoid and especially at the two colon flexures, problems regularly occur, including the risk of injury, pain to the patient, and cramp-like contractions of the colon, even up to the impossibility of continuing the examination. These problems are related to the fact that the colon is soft and fixed only relatively little in the abdomen. After a deflection, the principal direction of the force by which the colonoscope is advanced no longer is towards the distal end of the colonoscope but instead towards the readily yielding wall of the colon, a fact which is unpleasant for the patient. Therefore, the cecum cannot be reached in about 10 to 15% of all cases.
These difficulties can be overcome only in part by the customary inserting means since they are suitable for guiding the colonoscope only through the rectum and, at best, the sigmoid and the colon descendens. Yet the problems described continue to exist at the left colon flexure, at the latest. Moreover, many patients already find it unpleasant that the sigmoid is forced into an almost rectilinear shape by the slip tube since the configuration of the slip tube is not variable at random. Due to the great stiffness of the slip tube there is a risk of perforating the colon if the slip tube is handled carelessly.
A mechanical-pneumatical manipulation system for colonoscopes is known from DE 36 05 169 A1 where an inserting means is intended to make it easier for the physician and the patient to introduce a colonoscope. This inserting means, too, comprises a flexible slip tube into which the colonoscope can be slipped. A balloon or group of balloons of highly flexible material is arranged on the slip tube. In vented condition the balloon or group of balloons lies in close contact with the slip tube; in inflated condition the balloon or group of balloons is to find support in the surroundings, i.e. on the intestinal wall, and the shaft of the colonoscope is to be movable forwardly or backwardly with the aid of the mechanics. A second group of balloons firmly mounted on the colonoscope shaft are vented when the colonoscope is to be displaced with respect to the slip tube which is supported in the vicinity and they are inflated when the slip tube is to be displaced together with its balloon or group of balloons. The slip tube includes longitudinal passages one of which is intended to house pressure and vacuum conduits and another one to receive a mechanical push-pull system.
This inserting means with an inflatable balloon or a group of such balloons arranged at the outside cannot very much ease the insertion of a colonoscope into the human intestine because the intestine reacts in the same manner by spastic and painful contractions to every extension, regardless of whether it is caused by an unprotected colonoscope or by one or more blown up balloons. Such contractions also occur distally of the colonoscope and make it difficult to push it on. The known inserting means is not suited for non-medical objects of examination, such as parts of machinery which may have sharp-edged inner contours because a balloon assembly on the flexible slip tube is susceptible of damage.
The same applies mutatis mutandis to a device known from DE 28 23 025 C2 for transferring a colonoscope where the distal end of the colonoscope is connected by a thin, overturned hose to the distal end of a conical tube adapted to be introduced into the human anal ring. A housing enclosing the colonoscope and provided with a connecting socket can be screwed on to the proximal end of the tube. When a pressure medium is introduced through the connecting socket a portion of the hose located between the two hose ends is pushed into the large intestine while, at the same time, it turns inside out, pulling along the colonoscope. The latter thus is to move into the intestine by being pulled rather than pushed. As the hose advances, its interior is to turn inside out progressively so that then it will form an outer hose portion which does not move with respect to the mucous membrane of the intestine. However, that may also cause painful spastic intestinal contractions. Even if it is possible with this known device to advance a colonoscope far enough, especially all the way to the cecum, it is still not possible to leave the hose in the intestine and use it as an aid for the renewed insertion of the colonoscope if the latter has been pulled out preliminarily, for example to remove a larger polyp. The hose which can be overturned and consequently must be thin is not suitable for technical applications because it can tear easily at sharp edges and protrusions of the object under examination.